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NlTED 'rn'rns ;ATENT rFicE.

JOHN ERIKSON, OF PROVIDENCE, RHODE ISLAND.

ELECTRlCAL GAS-ALARM.

SPECIFICATIGN forming part of Letters Patent No. 586,813, dated July 20, 1897.

Application filed April 3 1897. Serial No. 630,540. (No model.)

To aZZ whom it may concern.-

Be it known that I, JOHN ERIKSON, of

' Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Electrical Gas-Alarms; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the ac companying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to that class of alarms intended to give warning if a gas-flame has been blown out instead of the gas being turned off, or if the stop-cock has accidentally been opened at any time. It is fully explained and illustrated in this specification and the accompanying drawings.

Figure 1 represents a side elevation of a V gas-burner with the appliance attached. Fig.

2 shows a back elevation of the gas-burner and the devices. Fig. 3 is a top view of the same. Fig. at is a separate view of the vertical plate. Fig. 5 is a separate view of the horizontal plate. Fig. 6 is a cam on horizontal plate. Fig. 7 shows side view of the bolt.

The object of this invention is to prevent the great trouble and danger arising from the stop-cock of a gas-jet being open and the gas not lighted, either because the flame has been blown out intentionally or accidentally instead of the gas being turned off or the stop cock has been opened unintentionally, and in either case to sound an alarm. This object I accomplish by using the heat of the gasfiaine to keep an electric circuit open that would otherwise be closed and sound an alarm if the stop-cock is open sufficiently to allow the escape of any gas.

The construction and operation of the device by which the desired result is obtained are as follows:

In the drawings, A is an ordinary gasknee is bent off at the top in the opposite direction to the base a and a notch 19 cut down vertically through it.

A block D, of wood or some other insulating material,is attached to the plate a at about midway up on its front by means of a screw andnut 0, and a loop J, of wire, of brass, copper, or other metal, is also attached to the plate a by means of the same screw, which passes through a ring in one end of the loop on the inner side of the plate a, while the other end of the loop comes down in front of the plate a and the free end passes through the notch?) in the knee as a guide. Two pieces of metal 8 s are held separately by screws on the top of the block D in position to receive the free end of the loop J between them and make a contact with both plates.

A plate P, the shape of which is seen in Fig. 5, is fitted to go on the stop-cock under the flat-head screw and washer that holds the plug h in place. This plate has two cars e e, turned up to hold a sliding bolt 7', which is pressed forward toward the burner by a spiral spring 0. This bolt r has a hole in its outer end and receives a wire 2), a part of the electric circuit; 4

A knee n is attached to the plate P by a bolt and an insulating washer c' is placed between the knee and plate, and a wire 4) is connected with this bolt and the screw that holds one of the pieces of metal 8 on the block D. A cam-shaped piece f (seen in Fig. 6) has a hole made through it to fit on the end of the plug with the usual portion of the circle left to fit in the gap in the end of the plug it and turn with it. This cam f has a projection h on it, placed so as to push against a shoulder y on the bolt 0" (see Fig. 7) and push it back when the cock is closed and break the contact between the end of the bolt and knee 'n, which breaks the circuit through the Wire 4) and wire 1), so that the alarm will never sound when the gas is entirely shut off.

The operation of the device is this: When the stop-cook is open, so that the gas will pass through the burner, the connection of circuit at knee n and inner end of the bolt 'rwill be completed by the spring 0 pressing the bolt against the knee, and if the gas is not lighted the free end of the loop .1 will press down in between the pieces 8 s and complete the circuit at that point, so that the electric current from wire 1; will pass around through the bolt 7', wire '12, through 8 s to the wire 2:, and the alarm will be sounded, but if the gas is lighted the heat of the flame will heat the inner leg of the loop J and, by expanding it, raise the free end of the loop out of contact with the blocks 5 s and break the circuit at that point, so as to stop the alarm from soundlng.

Having thus described my improvements, I claim as my invention and desire to secure by Letters Patent- 1. In a gas-escaping alarm, the combination with a burner and a stop-cock, of a loop of wire having one leg held stationary and the other leg left free to break or make an electrical circuit by heating or cooling one of the legs, with means operated by the stop-cock to close the circuit when the gas is turned on and break it when the gas is completely turned oif, and wires to form said electrical circuit, substantially as described.

2. In a gas-escapin g alarm, a plate attached on said plate, a wire attached to said bolt, a

wire attached to said plate, a spring on the bolt to press it into contact with the wire attached to the plate, a cam attached to the cock-plug arranged to push back the bolt and break its contact when the stop-cock is closed, substantially as described.

3. In a gas-escaping alarm, the combination of a plate attached to the burner, a loop of wire secured to the plate, said loop having one side exposed to the gas-flame, the other side of the loop being arranged to make an electrical connection between two plates when the gas is not burning and wires at tached to said plates to connect with a source of electricity, substantially as described.

In testimony whereof I have hereunto set my hand this 31st day of March, A. D. 1897.

JOHN ERIKSON.

In presence of- BENJ. ARNOLD, HOWARD E. BARLoW. 

